Interactions between "What" and "When" in the Auditory System: Temporal Predictability Enhances Repetition Suppression
Interactions between "What" and "When" in the Auditory System: Temporal Predictability Enhances Repetition Suppression
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DOI：
10.1523/jneurosci.2599-11.2011
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发表时间：
2011-12-14
影响因子：
5.3
通讯作者：
Escera, Carles
中科院分区：
文献类型：
--
作者：
Costa-Faidella, Jordi;Baldeweg, Torsten;Escera, Carles
听觉系统中的神经活动随着重复刺激而减少，在多个时间尺度上匹配刺激概率。这种现象被称为刺激特异性适应，被解释为规则性编码帮助听觉对象形成的神经机制。然而，尽管大量的文献涵盖了从单细胞到头皮神经诱发电位（AEP）的记录，但刺激时间却没有引起多大兴趣。在这里，我们调查了时间的可预测性是否增强了与刺激概率编码相关的神经活动的经验依赖性调制。我们使用人类电生理记录的健康参与者谁暴露于被动听的声音序列。不同频率的纯音以不同重复次数的连续序列进行传递，从而能够研究AEP中的顺序重复效应。在可预测的时间条件下，音调与等间隔的刺激间隔;在不可预测的时间条件下，刺激间隔随机变化。我们的研究结果表明，不可预测的刺激时间取消了重复积极性的早期部分，AEP索引听觉感觉记忆痕迹的形成，而留下的后期部分（类似于> 200 ms）不受影响。这表明，时间的可预测性有助于传播的重复效应上游的听觉通路，最有可能从协会听觉皮层（包括颞平面）向初级听觉皮层（Heschl的回）和超越，判断AEP lavelets的时间。这一结果呼吁注意刺激时机在未来的实验中，关于感官记忆痕迹形成AEP措施和刺激概率编码的动物模型。
Neural activity in the auditory system decreases with repeated stimulation, matching stimulus probability in multiple timescales. This phenomenon, known as stimulus-specific adaptation, is interpreted as a neural mechanism of regularity encoding aiding auditory object formation. However, despite the overwhelming literature covering recordings from single-cell to scalp auditory-evoked potential (AEP), stimulation timing has received little interest. Here we investigated whether timing predictability enhances the experience-dependent modulation of neural activity associated with stimulus probability encoding. We used human electrophysiological recordings in healthy participants who were exposed to passive listening of sound sequences. Pure tones of different frequencies were delivered in successive trains of a variable number of repetitions, enabling the study of sequential repetition effects in the AEP. In the predictable timing condition, tones were delivered with isochronous interstimulus intervals; in the unpredictable timing condition, interstimulus intervals varied randomly. Our results show that unpredictable stimulus timing abolishes the early part of the repetition positivity, an AEP indexing auditory sensory memory trace formation, while leaving the later part (similar to > 200 ms) unaffected. This suggests that timing predictability aids the propagation of repetition effects upstream the auditory pathway, most likely from association auditory cortex (including the planum temporale) toward primary auditory cortex (Heschl's gyrus) and beyond, as judged by the timing of AEP latencies. This outcome calls for attention to stimulation timing in future experiments regarding sensory memory trace formation in AEP measures and stimulus probability encoding in animal models.